As of last Friday, it was still in mock-up mode. If I were to speculate, I would say that releasing more pictures now would just confuse people and spur more questions than answers, especially as some of the things on the mock-up are clearly going to be changed before a production model is finalized. It might also leave people feeling let down if features that are implied by photos are not included in the end result.
Of course, it may be that Mr. Bihn is trying to teach the world patience and has chosen his own consumers as among the first to benefit from his instruction.

